Butt type electrical contact



April 23, 1968 N. L. MOULIN BUTT TYPE ELECTRICAL CONTACT Filed March 5, 1966 Fig. 2.

Norbert L. Moulin,

INVENTOR.

BY. um a 2:546

ATTORNEY.

United States Patent 3,380,012 BUTT TYPE ELECTRICAL CONTACT Norbert L. Moulin, Placentia, Calif., assignor to Hughes Aircraft Company, Culver City, Calif., a corporation of Delaware Filed Mar. 3, 1966, Ser. No. 531,428 4 Claims. (Cl. 33995) ABSTRACT OF THE DISCLOSURE In the disclosed electrical connector, the female member has a tubular portion which, where contact is to be made with the male member, defines a plurality of spiral slots. A recession on the end of the tubular portion, having a shape complementary to that of the tip of the male member, receives the male member as it is inserted within the female member. The spiral slots permit both a compression and a rotation of the tubular portion as it is deformed by the coupling force.

This invention relates to an improved electrical contact and more particularly to an electrical contact of the butt type having greatly simplified construction and improved reliability.

With the increasing use of electrical equipment and electronic circuits and components has come a demand for simple, reliable devices for interconnecting such equipment.

Therefore, an object of the present invention is to provide an improved butt-type electrical contact of simplified construction.

A further object of the improved butt-type electrical contact of the present invention is to provide an electrical contact which mates in a wiping action to increase its reliability.

A still further object of the improved electrical contact of the present invention is to provide an electrical contact which is self-centering.

The aforesaid and other objects and advantages are accomplished according to the present invention in an electrical connector which comprises a pair of mateable members each constructed to have an electrical conductor affixed thereto. One of the contact members contains a pin-like end portion, while the other member includes a spring-like rotatable portion which may include a detent for receiving the end portion. This rotatable portion includes in a preferred embodiment spiral slots which function like coils of a spring to cause it to rotate and deflect when engaged by the other contact member. In a conventional manner both of the contact members include retaining springs for securing them in chambers in connector bodies.

These and other objects and advantages of this invention will become apparent from the following description considered in conjunction with the accompanying drawings throughout which like reference characters indicate like parts and in which:

FIGURE 1 is a perspective view of a preferred embodiment of the improved electrical contact of the present invention; and

FIG. 2 is a side elevational view of the portion of a pair of connector bodies and electrical conductors illustrating the securing of the improved electrical contacts of the present invention in chambers in the bodies.

Referring first to FIG. 1, the improved electrical contacts of the present invention comprise a first or male contact member or element and a second or female contact member or element 12. The male element is generally elongated in shape having one extremity formed into a tip portion 14 which may be blunt or, if desired,

hemispherical or other similar shape, and the other end having an electrical conductor termination in the form of a chamber 16 for receiving and retaining an electrical conductor. The female element, like the male element, is generally elongated in shape and includes at one end a chamber 16 for receiving and retaining an electrical contact; however, at the other end it includes a rotatable portion 18.

The rotatable portion 18 has a generally cylindrical shape and includes a plurality of spiral slots 20 spaced around its circumference. The spiral slots 20 are of a size and location that permits the rotatable portion to function like a plurality of stacked coaxial springs when it is contacted by the tip portion 14 of the male element 10. The extremity of the rotatable portion 18 may include a detent 22 of a shape substantially similar to that of the tip portion 14 of the male element. This permits the improved electrical contact to be self-centering since the engagement of the curved surfaces of the tip 14 and detent 22 causes the respective contact element to be slightly deflected into alignment although initially their longitudinal axes may not be aligned. Since the rotatable portion 18 functions in a spring-like fashion, the force of contact of the elements causes the rotatable portion 18 to rotate and since the male element 10 is held substantially stationary this causes the detent 22 to slide over the tip 14 resulting in a wiping action between the contact elements.

While the present embodiment has been illustrated to include a rotatable member 18 having spiral slots 20, it should be understood that since this member functions in the nature of a spring, if desired, the female element 12 could be made from two parts, one a coil spring and the other a cylindrical portion containing the electrical conductor termination chamber. Further, it should be understood that in both embodiments, depending upon the amount of rotation desired and the nature of the contact force, the physical properties of the rotatable portion whether it comprises a spring or cylindrical member having spiral slots may be varied.

For the most efficient and reliable operation of the rotatable member 18, it has been found that the spiral slots 20 should have a total area within the range of 30% to 60% of the total area of the outer surface of the rotatable member and should be positioned with its longitudinal axis at an angle relative to the longitudinal axis of the female element 12 within the range of 30 to 60 degrees of arc. Below the lower values of these ranges of size and location the rotatable member 18 may not rotate sufliciently under a conventional contact force to permit sufficient wiping of the contacts and above these ranges the rotatable portion 18 may rotate more than desired which may result in excluding the elastic limit of the material of the contact, thus preventing its return when the contact force is removed. In this regard, it is desirable to manufacture the contact out of a material having high electrical conductivity and good spring prop erties, such materials being alloys such as beryllium copper, or Phosphor bronze.

Referring now to FIG. 2, intermediate the ends of both of the contact elements 10 and 12 is a reduced diameter portion 2 4 shown best in FIG. 1 in which is positioned a conventional retaining clip 30. It is the function of the clip 30 to deflect sufficiently to permit the contact element to be inserted into a chamber 32 in a connector body 34 and then once inserted expanded into engagement with the annular retaining shoulders of a reduced diameter portion 36 to retain the contact element in the connector body 34.

While the basic principle of this invention has been herein illustrated along with one embodiment it will be appreciated by those skilled in the art that variations in the disclosed arrangement both as to its details and as to the organization of such details may be made without departing from the spirit and scope thereof. Accordingly, it is intended that the foregoing disclosure and the showings made in the drawings will be considered only as illustrative of the principles of the invention and not construed in a limiting sense.

What is claimed is:

1. An electrical contact comprising:

a first contact element including a tip portion and a conductor termination portion for retaining an electrical conductor; and

a second contact element including a rotatable portion having means for receiving said tip portion in abutting relationship and a conductor termination portion for retaining an electrical conductor, which permit a portion of said tube to rotate around substantially the longitudinal axis of said second contact element as said first and second contact elements are engaged,

whereby engagement of said tip portion and said means causes rotation of said rotatable portion.

2. The electrical contact of claim 1 wherein the area of said spiral slots is more than 30% but less than 60% of the total area of the outer surface of said rotatable portion.

3-. The electrical contact of claim 1 wherein each of the slots is oriented with its longitudinal axis at an angle with the longitudinal axis of the rotatable portion which is greater than 30 degrees of are but less than 60 degrees of arc.

4. An electrical connector comprising:

a pair of connector bodies each including at least one chamber having a reduced diameter portion;

a first contact element positioned in the said chamber of one of said bodies, said contact element having a .4 blunted tip portion at one end of said chamber and a conductor termination portion at the other end of said chamber;

a second contact element positioned in the said chamber of the other of said bodies and aligned for engagement with said blunted tip portion of said first contact element and including at one end a rotatable portion having a contact surface complementary to said blunted tip portion for receiving Said tip portion in abutting relationship, said rotatable portion defining a hollow cylindrical tube having a plurality of spiral slots around its periphery which permit said tube to rotate around substantially the longitudinal axis of said second contact element as said first and second contact elements are engaged, said second contact element further having a conductor termination portion for retaining an electrical conductor at the other end of said chamber of said other of said bodies; and

'a retaining spring circumscribing each of said first and second contact elements intermediate the ends thereof and engageable with said reduced diameter portion of said chambers for retaining said contact elements in said connector bodies.

References Cited UNITED STATES PATENTS 1,349,405 8/1920 Brown 33948 1,390,607 9/1921 Farmer 33948 1,392,558 10/1921 Darrah et a1. 339-48 2,742,626 4/1956 Collins et a1 339-255 FOREIGN PATENTS 941,840 11/ 1963 Great Britain.

MARVIN A. CHAMPION, Primary Examiner. JOSEPH H. MCGLYNN, Assistant Examiner.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,380 ,012 April 23 1968 Norbert L. Moulin It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 62, "the" should read a Column 3, line 17, after "conductor," insert said rotatable portion defining a contact surface and further defining a hollow cylindrical tube having a plurality of spiral slots around its periphery Signed and sealed this 2nd day of September 1969.

Commissioner of Patents WILLIAM E. SCHUYLER, JR. 

